Re: [Lzip-bug] adding lunzip or something like that

[Antonio Diaz Diaz]

Hello Daniel,

Daniel Baumann wrote:
> most compressors offer a 'dedicated' uncompression binary, e.g. gunzip
> or bunzip2. in order to use lzip as a drop-in replacement in such
> situations, how about adding a lunzip binary equivalent to 'lzip -cdfq'?

As Mario points out, those are not dedicated binaries but links, copies 
or one-line scripts calling "$tool -d".

Using links or copies is disapproved by the GNU Coding standards[1]:
[1]http://www.gnu.org/prep/standards/html_node/User-Interfaces.html#User-Interfaces

"Please don't make the behavior of a utility depend on the name used to 
invoke it. It is useful sometimes to make a link to a utility with a 
different name, and that should not change what it does."


As bzip2 is not trying to be part of GNU, bunzip2 is a copy of bzip2 (cp 
-f bzip2 $(PREFIX)/bin/bunzip2). The effect is more or less the same as 
a link, only more wasteful (and perhaps more compatible with non-posix 
systems).

Gunzip OTOH, is a script calling "gzip -d", which just adds another 
dependency to the projects calling gunzip, making them more fragile in 
return for nothing. Automake[2], for example, has already stopped using 
gunzip, bunzip2, etc.
[2]http://www.sfr-fresh.com/unix/misc/automake-1.11.1.tar.gz:a/automake-1.11.1/ChangeLog

"Replace unlzma, gunzip, bunzip2 with pack tool -d invocation.
 * lib/am/distdir.am (distcheck): Use lzma -d, gzip -d, bzip2 -d,
 instead of the respective un$tool invocation, to avoid depending
 on another tool."


Maybe offering a dedicated uncompression binary (including only the 
decompression code) could make sense for embedded devices, but offering 
a link, copy or script does not make sense in any case.

So the best way for lzip to become a drop-in replacement for gzip and 
bzip2 is that gzip and bzip2 stop shipping those fake decompressors and 
people stop using them.

Pretending that people stop using fake decompressors may sound 
unreasonable but:
1) Doing it would benefit everyone; we would have more robust, less 
bloated software.
2) There is no "untar", but people happily uses "tar -x" instead.
3) "Reasonable people adapt themselves to the world. Unreasonable people 
attempt to adapt the world to themselves. All progress, therefore, 
depends on unreasonable people. (George Bernard Shaw)"


Best regards,
Antonio.